Experimental Study On Behavior Of Strength And Deformation Of Cemented Coarse-grained Soil

Cemented coarse-grained soil is a stone material, which is take advantage of natural (or through the simple process of) sand and gravel, excavated materials or other easily accessible rock materials (including the low strength materials that conventional concrete can not use), and compacted by adding an appropriate amount of mixing water and cement materials. Domestic and international research in this area has just started, mostly learn from concrete research methods, research mix, and rate and curing time and other factors on the mechanical properties of materials, uniaxial compression can not considered strength and deformation characteristics of cemented coarse-grained soil under complex stress condition, such as pressing hard, dilatancy and so on. Triaxial test on the mechanical properties of cemented coarse-grained soil is scarce, and size selection is limited by the test equipment, the maximum diameter is only 10mm. The major purpose of this paper is to study the influence of different confining pressures, different cement content, different curing ages, and different relative density of on strength and deformation characteristics of cemented coarse-grained soil, to summary the change of the parameter, to provide the basis for the model of stress and strain of cemented coarse-grained soil.The results show that:After the destruction of cemented coarse-grained soil, the sample with obvious features of brittle failure can be seen obvious local shear band, and the change of shear strength have a certain relationship with the formation of local shear bands. When axial strain is small, the volume of soil decreased, shear strength increased. Then the volume of soil increased with the development of deformation. When shear strength is the maximum, dilatancy become increasingly evident. With the continuous development of the dilatancy, the shear strength of soil become less and less, he soil is in the state of strain-softening. When dilatancy of the soil is steady, shear strength of the soil has reached a stable stage.With the increase of confining pressure, initial modulus also increased, but the increase is not obvious, peak strength and residual strength increased significantly. With the increase of cement content, the peak strength and residual strength increased. With the increase of curing time, the peak strength increased to some extent. As the relative density increases, the peak strength and residual strength have increased. Though the parameters of non-linear strength, we know:as curing time increases,φ0 increases,Δφdecrease; as the increase of cement content,φ0 increases,Δp decrease; as the increase of relative density,φ0 increases,Δφdecrease.Part of the soil dam is replaced by cemented coarse-grained soil, which can increase the overall stability of the soil dam.